EXT JS How to check field on form opening?

I have order form which contains combobox field. When user select specific value, system enables new set of fields in form. This part of code looks like:

if (action.result.data.field == "1") {
     Order.query('fieldset[itemId="set1"]')[0].enable();
     Order.query('fieldset[itemId="set2"]')[0].show();
   }

But if user open editing form with already selected specific value, system doesn't show this set of fields. I need system to check specific value on opening the edit form. What class I should use?